Manufacture of mono-acylated ethylene-diamine and its derivatives



Patented Sept. 5, 1933 PATENT OFFICE MANUFACTURE ETHYLENE-DIAMIN TIVES F MONO-ACYLATED E AND ITS DERIVA- Karl Wilhelm Rosenmund, Kiel, Germany No Drawing. "Application June 19, 1931, Serial No. 545,620, and in Germany October 31, 1929 13 Claims.

A patent application has been filed in Germany on October 31, 1929. v

This invention has reference to the manufacture of monoacyl-compounds of bivalent amines and of their derivatives, and it refers more particularly to monoacyl-compounds of ethylenediamine and of derivatives thereof, and it is intended among other objects to devise means of obtainingv a greater range of such compound than was obtainable heretofore. and to improve and facilitate the process of manufacture generally.

The manufacture of monoacyl-compounds of ethylene-diamine with acyl-groups of higher fat ty acids is well known. The usual process of their manufacture consists in the treatment of ethylene-diamine with esters, chlorides or anhydrides of higher'fatty acids. Attempts to manufacture monoacyl-compounds of lower fatty acids in the same manner by means of chlorides or anhydrides however'resulted merely in the production of diacyl-compounds. It has also become known from the prior art that ethylene-diamine fails to yield monoacyl-compounds for instancewith aceto-substituted acetic acid ester and cyanacetic acid ester, and it has been ascertained by investigations that benzoic-acid esters, when heated with ethylene-diamine yield only diacylcompounds, so that there was no possibility of obtaining monoacyl-compounds in accordance with the methods of the prior,- art.

It was obvious that higher fatty acids should react in a different manner than lower fatty acids, inasmuch as higher fatty acids and their derivatives are differentiated from the corresponding compounds of the lower fatty acids by their reduced chemical activity. Yet, from my investigations the unexpected result has been derived that the esters, but not the anhydrides 40 and chlorides of the lower fatty acids produce a very good yield of the desired monoacyl-compounds. By this treatment mainly the monoacylated compounds are obtained, while only very small quantities of diacyl-derivatives are formed.

The lower homologues of the monoacyl-compounds are very similar to each other. They constitute basic substances, capable of distillation, and chemically reactive. On account of their chemical and physical properties they are very suitable to serve as materials for the production of various compounds and preparations of high importance inthe arts and for therapeutic uses.

The reaction in my invention takes place according to the following formula:

In my invention ethylene diamines having the generic formula NHKCH2- CH2-- NHK1 are mixedand heated with esters of aliphatic monobasic carboxylic acids containing not more than 10 carbon atoms to form monoacyl compounds of ethylene diamines, these compounds having the generic formula NI-IK-'C H2-C H2--NK1-'C O-R K and K1 in the above formula representing hydrogen or alkyl groups and COR representing the acyl group of an aliphatic monobasic carboxylic acid containing'not more than ten carbon atoms.

Esters of non-substituted mono-carboxylic acids with not more than 10 carbon atoms react readily, no matter whether the carbon-chain is straight or branched out. The yields vary between and Examples in which use is made of fatty acids with straight carbon-chain and with branched out chain, and with saturated and unsaturated chains, and of N-alkylated ethylene-diamine with secondary amino-groups are hereinafter enumerated, viz:-'

(1) 1 molecule of ethyl acetate and 1.2 molecules ethylene-diamine-hydrate having the formula C2H4(NH2)2.H2O, are heated to degrees Celsius for several hours under pressure, for instance, in an autoclave. The solution is freed by fractionation from the alcohol formed and from the excess of ethylene-diamine and is distilled under a high-vacuum. The resultant mono-acetyl-ethylene-diamine boils at -140 degrees Celsius under an absolute pressure of It constitutes a water-soluble oil Celsius.

By using instead of the butyric acid ester other aliphatic monobasic carboxylic-acid esters, for example esters of propionic acid, iso-butyric acid, iso-valerianic acid, crotonic acid and di-ethylacetic acid the corresponding monoacyl-compounds may be obtained. They all constitute viscous, basic liquids. Their respective boiling points are as follows:-

Boiling point in fgfgf P Yield degrees C.

Mono butyryl ethylene Percent diamine 138-145 1. 8-2. 2 7O Mono iso butyryl ethylene-diamine 140-150 1. 8-2. 2 Mono-iso-valeryl thylenediamine 136-142 1.3-2. 2 70 Mono-diethyl-acetyl-ethyl- Y V ene-diamine 152-168 1. 8-2. 2 Mono crotonyl ethylene diamine 160-170 20 60 Mono propionyl ethylene diamine 138-143 2. 0 80 (3) Cyclohexyl monoacetyl-ethylene-diamine is obtained as follows:-5 grams cyclohexyl-ethylene-diamine are heated with somewhat less than the calculated amount of ethyl acetate at 110 degrees Celsius'under pressure andthe product obtained is distilled under high vacuum. It constitutes a thick, basic oil, having a boiling point of 168 degrees Celsius at 2.2 millimeters. Yield 75%. I Its hydro-chloride salt melts at' 186 degrees Celsius. I

The cyclohexyl-ethylene-diamine used was obtained by the catalytic reduction of the constituents of a molecular mixture of ethylene-diamine and 'cyclohex'anone according to the formula:---

CsHIoO-PNH2CH2CH2NH2+H2= V It should be understood that the scope of the invention is not to be limited to nor restricted by the examples herein described merely as illustrations of the embodiment of this invention, the invention being susceptible of modifications and changes of material and quantities thereof, ex-

cept as otherwise appears from the appended ing the generic formula O nnlon cnmno in which COR represents an aliphatic acyl radical.

2. Mono-butyryl-ethylene-diamine boiling at 150-160 degrees Celsius.

3. Mono-acetyl-ethylene-diamine constituting a basic, water soluble oil, and boiling at 135-140 degrees-Celsius under 2 millimeters pressure.

4. In the manufacture of aliphatic monoacyl compounds of ethylene diamine, the process which comprises mixing and heating together ethylene diamine with an ester of an aliphatic monobasic carboxylic acid containing not more than ten carbon atoms, and recovering the resulting monoacyl compound from the reaction mixture.

5. In the manufacture of aliphatic monoacyl compounds of ethylene diamine, the process which 2 comprises mixing'and heating together an ethylene diamine having the generic formula NHKCH2CHz-'NHK1 with an ester of an aliphatic monobasic carboxylic acid containing not more than ten carbon atoms and recovering the resulting monoacyl compound from the reaction products: K and K1 in the above formula representing hydrogen or alkyl groups.

6. The process of claim 5 wherein the reaction is conducted. at superatmospheric pressures.

, 7 The process of claim 5 wherein the monoacyl compound is recovered from the reaction products by distillation.

8. The process of claim 5 wherein the reaction is conducted at superatmospheric pressures, at temperatures of about to C. and wherein the said ester is unsubstituted.

9. Monoacyl compounds of ethylene diamines having the generic formula NHKCH2CH2 NK1-COR wherein K and K1 represent hydrogen or alkyl groups and CO -R represents the acyl group of an aliphatic monobasic carboxylic acid containing not more than ten carbon atoms.

KARL WILHELM ROSENMUND. 

